Analytical Services news

Listeria causes Listeriosis, a potentially serious infection
8 August 2017

Listeria test turnaround time halved

A rapid commercially available test for Listeria has the potential to open up new food export markets and save producers time and money. Cawthron has recently received IANZ accreditation for a PCR (polymerase chain reaction) test to detect Listeria in food and environmental swabs. This will cut sample processing time from two days to one.

This significant improvement in turnaround time means producers can clear their product faster and therefore potentially ship exports earlier.

New Zealand King Salmon Quality Manager Denver McGregor advised what this means for their product.

“The ability this [PCR test] gives us is time, and time is very important with a highly perishable product. There is an opportunity in a one day turnaround test for our shorter shelf life products to enter new international markets.

“The other opportunity is for faster feedback on clear results for environmental testing. Should there ever be an issue we will know a day earlier if we’re on the right track to resolving it,” said Mr McGregor.

Listeria causes Listeriosis; a potentially serious infection most likely to affect pregnant women, newborn babies, the elderly, and those with weakened immune systems. Ready-to-eat food products are most at-risk and Ministry for Primary Industries (MPI) works with producers and laboratories to guarantee regular testing.

The newly accredited Cawthron PCR Listeria test is based on extensive research. Cawthron Microbiology Section Head Mark Englefield explained it was important to ‘test the test’ thoroughly before bringing it to market.

“As new technology comes to the fore, so do opportunities for us to improve our services. PCR technology has traditionally been used for research purposes, but we recognise the opportunity to apply it to food safety testing.

“Our team considered and tested many options with timeliness, reliability, and commercial viability the primary criteria.

“The result is a robust and commercially-tailored test, which offers great value and a one day turnaround time,” said Mr Englefield.

Cawthron senior scientist Dr Jonathan Banks worked with the microbiology team to investigate the reliability of potential PCR tests for Listeria.

“Molecular monitoring tools have many exciting applications. We have significant molecular capability at Cawthron, and we are focussed on applying this expertise to food safety testing,” said Dr Banks.

The recently accredited PCR test for Listeria joins the Institute’s portfolio of food safety and value-add tests offered to food producers.

For more information on Cawthron’s services visit